Type is optional, defaulted to "abbr" if it is not empty it will be considered as "acronym" and used so to define the appropriate html tag as well as the class associated with this tag

Short is mandatory and represents the abbreviation you want to explain

Long is optional and represents the explanation you want to display when the mouse is over the abbreviation or the acronym. If empty, the long description of a previously used similar tag in the same page will be displayed (so if you use several times CMS in a same page you may have the second and later occurence defined as {{abbr short="CMS"}})